ATLAS OF CANADA OPEN-SOURCE GIS TOOLS
rupert at rupertbrooks dot ca
IMPORTANT: I get a lot of spam, and sometimes i miss real mail inadvertently.
If you email me, please put "ATLAS TOOLS"
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Atlas of Canada
GeoAccess Division, Canada Centre for Remote Sensing
Unfortunately, the actual release of these tools has been very
slow in coming. I left the Atlas to pursue a Ph.D before they could
be released, and development has been erratic at best since then.
One could easily ask why, if these tools had been used at the Atlas
was it not simply a matter of putting them online. The answer is that
the tools as they were actually used were a nightmarish hack of tangled
code that was totally unsuitable for release. See the design discussion
for more information.
As of this release, hydrology generalization and the construction of
perceptual strokes are working. There are two major parts missing.
The skeletonization is nearly there - a totally new and improved variation
is almost done. The road generalization will not be done in the forseeable future. Given that the perceptual strokes are working now, however,
the interested reader could probably put something together themselves.
TABLE OF CONTENTS / SITE MAP
This website is organized as follows. Changes will be indicated
in the Updates section.
October 10, 2003 - Andy Murray has provided an aml for selecting downstream arcs. Thanks Andy (Download it).
October 10, 2003 - Updated some blunders in the documentation that Andy found.
June 16, 2003 - net, tri and agg are finally online. Some parts of
tri are rather beta, in nature, see below for details.
June 16, 2003 - got rid of the mailing list. No one used it - just
email me directly.
August 30, 2002 - updated information about my leaving
July 18, 2002 - presentation from workshop; Disp information added
June 15, 2002 - First placed online.
Over the past several years, software applications addressing problems
in automated generalization and computational geometry have been developed
at the National Atlas of Canada. These applications are now being released
under an open-source license in the hopes that other researchers may be
able to provide feedback or potentially benefit from access to the code.
There are four different applications:
These generalization algorithms have been used successfully in
practice for the production of a 1:4 000 000 scale map of Canada’s
Northern Territories. The network analysis and Voronoi algorithms
have been used in the production of a set of topologically integrated
drainage areas for Canada’s rivers.
Net: a set of tools for the analysis and generalization of networks, in
particular for the generation of perceptual strokes.
Tri: a tool for the generation of approximate Voronoi diagrams for planar
graphs, and the generation of medial axes. An exaggeration algorithm
for area features based on the medial axis is described
Agg: a tool for the aggregation of multi-classed area patches.
Disp: a displacement algorithm
simple terms, anyone may use this software as they see fit, but may
not claim it as their own work. The copyright in the software remains
the property of Canada. Neither Canada nor the author accept any
liability whatsoever for any consequences of your using this
software. Please read the license to determine exactly your
rights and requirements when using this software.
Anyone with interest is encouraged to use, extend and experiment with this
software. Please read the license, and
bear in mind that neither Natural Resources Canada nor the author accept
any liability whatsoever for any problems you may encounter.
Comments, suggestions, complaints
or bug fixes are all welcome and should be sent to my email above.
- Thanks go to the Atlas of Canada for paying for me to revise
and complete parts of the project over the past year.
- Thanks also to Andy Murray, who has been using the software and gradually testing it.
Hydrology generalization and directionality determination algorithms based
on work by Dianne Richardson, especially the GenSystem software
Perceptual strokes based on work by Robert Thomson and Dianne Richardson
Lesley Chorlton was one of the first people to experiment with Agg and
provided a tremendous amount of valuable input.
Catherine Dussault implemented several important modules in the Agg system.
Mireille Bruel investigated the application of Agg, and made valuable suggestions
for its improvement.
Jorg Sack, Doron Nussbaum and Ji Chen were instrumental in exploring the
parallel implementation of the Displacement algorithm
Some of the coding for Hydrology and road network tools implemented by
Chris Gold provided very helpful suggestions for the approach to the approximation
of the voronoi diagram of a planar graph.
please send comments to rupert at rupertbrooks dot ca
Last modified: Wed Jan 16 17:54:15 EST 2008